In the interviews with JBL engineers themselves, they openly admit that beryllium is top-of-the-class.
Basically, if you want the very best, and cost is no object, beryllium is it.
One solution that I like personally, is the combination of a small neodymium tweeter with some midranges on a Unity horn. This offers the 'sweetness' that you get with a small tweeter, along with bandwidth that exceeds what a beryllium compression driver can accomplish.
On the downside, putting holes in the waveguide hurts the overall response.
On the upside, the cost is about 10X cheaper than a beryllium compression driver.
My other hobby is bicycles.
In the bicycle community, there are endless horror stories about Chineses factories manufacturing knock-offs of popular designs. I get the impression that the factories don't know the first thing about what they're copying.
You see this with a lot of products from Pyle. Some of their waveguides are excellent. For instance, Pyle's clone of the JBL PT waveguide is nearly indistinguishable from the real thing. OTOH, they sell some clones of Electrovoice horns from the 80s, and the throat is easily 20% too big.
Anyone who knows how audio works can recognize that a 20% gap in the throat will make the horn unusable, but some dude at a factory in China just had no idea that it was a problem. They're copying products that they don't understand.
If you think this is bad, here's one of my stories from my day job:
During the day, I write, support and develop software. A few years back, I was introduced to a small company that was deploying a piece of software at a company that's a household name. (Name redacted, of course.)
The company was a grand total of four employees. They had a salesman, a CEO, a PM and one "techie."
I was personally working with the techie, to get the software deployed. (My employer purchased the software.)
Within a few days, it was clear to me that all they'd done was steal a piece of open source software, remove the original author's names, and replace it with their own. This company had basically taken a piece of software which is free, added a couple of bells and whistles, and then re-packaged it and sold it to my employer.
Of course, my employer could have simply used the FREE software, but the author of the FREE software wasn't a salesperson. They'd created the software to solve a problem, and then they'd moved on to something else, like engineers do.
One day I came to work, and the "techie" that I was working with looked like he'd seen a ghost. While we're working on the install, he reveals that the company he works for had been acquired. Because there were only four employees, he'd become a millionaire overnight. A multi-billion dollar company had acquired his employer, lock stock and barrel, and his equity stake was now worth seven figures.
If you look at the history of Linux, it's a similar story. Giant chunks of it were brazenly stolen from the original authors of UNIX.
I built a pair of Volt-6s and a single Volt-8 last weekend to use as surrounds and center channel, respectively, in my living room home theater. But first I hooked up the 6s to my two channel system in a different room to give them a test run. WOW. While I wouldn't call them true hi-fi speakers, between the output capabilities and the coaxial design, they sound amazing (augmented by a powerful array of subwoofers).
I'm now absolutely replacing the speakers in that system with a pair of the Vortex-12s (the 15s definitely won't fit, unfortunately).
Biggest question for me is whether I want to wait for the flatpacks. I do want to try my hand with cabinets someday, but the DIYSG flatpacks are so affordable and easy.
I'm now absolutely replacing the speakers in that system with a pair of the Vortex-12s (the 15s definitely won't fit, unfortunately).
Biggest question for me is whether I want to wait for the flatpacks. I do want to try my hand with cabinets someday, but the DIYSG flatpacks are so affordable and easy.
Great "instant millionaire" story. I hope techie had the sense to jump ship before the Co.'s new owner found out that all its acquisition does is remarket public domain code 
As for Linux, I don't claim your IT background, but tend to concur. UNIX was an AT&T/Bell Labs product from 1969?-early 1980s, they were not allowed in the computer business, so UNIX was refined in academia. Then they were allowed to make it a commercial product! WTF? Did all those university coders get compensated? I doubt it. So you could argue that it should have been open source from the start. In any case, I never heard that AT&T or its descendants ever made any money on Unix licensing. Remember, imitation is the sincerest form of flattery; problem is sometimes it can be deemed "intellectual property theft." But is it any wonder the minnows robbed the "Whale" blind: The company is a regulated public utility, no wait, it's a for-profit company, no wait, it is a dozen Baby Bells, no wait, it's Lucent, no wait [my knowledge fades by early 90s, I have no idea what tumult has happened since...]
As for Linux, I don't claim your IT background, but tend to concur. UNIX was an AT&T/Bell Labs product from 1969?-early 1980s, they were not allowed in the computer business, so UNIX was refined in academia. Then they were allowed to make it a commercial product! WTF? Did all those university coders get compensated? I doubt it. So you could argue that it should have been open source from the start. In any case, I never heard that AT&T or its descendants ever made any money on Unix licensing. Remember, imitation is the sincerest form of flattery; problem is sometimes it can be deemed "intellectual property theft." But is it any wonder the minnows robbed the "Whale" blind: The company is a regulated public utility, no wait, it's a for-profit company, no wait, it is a dozen Baby Bells, no wait, it's Lucent, no wait [my knowledge fades by early 90s, I have no idea what tumult has happened since...]
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I heard back from Erich. Tower-style flat packs are planned for the Vortex lineup “at some point” but Erich doesn’t know when, as he’s still waiting on the cabinet company he uses to deliver the 15” subwoofer enclosures that were supposed to be delivered last month.
Not great news, I know. I personally was looking forward to using a pair of Vortex 15 as mains while I finished getting the 3D printer up and running to print Bill Waslo’s unity horn, for which I already have the drivers. I could try building my own enclosure but I’m not much of a carpenter, perhaps now’s the time to address that.
Not great news, I know. I personally was looking forward to using a pair of Vortex 15 as mains while I finished getting the 3D printer up and running to print Bill Waslo’s unity horn, for which I already have the drivers. I could try building my own enclosure but I’m not much of a carpenter, perhaps now’s the time to address that.
Are there affordable alternative material for the CD diaphragm that comes close? Peerless' recent titanum ones have great bang for buck but still doesnt come close to even the latest home audio ones like SB ring radiators.
So what if we have a home audio beryllium tweeters and top of line Scanspeak/Satori drivers in a unity horn?
The advantage of beryllium is bandwidth. This means you have three options:
option 1) You spend $500 for a beryllium tweeter with wide bandwdith
option 2) you spend $50 for a one inch tweeter with an aluminum dome that runs out of steam at 16khz
option 3) you spend $25 for a 3/4" tweeter with a 3/4" dome that plays to 24khz. On the downside, it's maximum output is terrible. On the upside, you can fix that with a waveguide.
option 1) You spend $500 for a beryllium tweeter with wide bandwdith
option 2) you spend $50 for a one inch tweeter with an aluminum dome that runs out of steam at 16khz
option 3) you spend $25 for a 3/4" tweeter with a 3/4" dome that plays to 24khz. On the downside, it's maximum output is terrible. On the upside, you can fix that with a waveguide.
Looks like "TeXtreme" may be a more affordable and even wider bandwidth alternative to beryllium:
N314X-8 - Drivers | Eminence Speaker
Am I correct that it could be EQ'd flat to 500 hz at 100db sensitivity in a home usage environment, based on the measurement graph? Glenn.
Well, good to know that I ought to just move forward with my own cabinets. It will be a fun project for me; I just liked the idea of avoiding the extra expense.
It's too bad that this project, which seems like it has been a big, expensive commitment for him, has been hampered a bit by troubles with the flatpacks.
I've finally decided to move ahead with building a pair of these and ultimately couldn't resist going with the Vortex-15 instead of the 12. They will be a tight fit in my current space, but I figure these are drivers I'm going to want for the long haul so why compromise. For now they're going to be simple Duratexed MDF ~2.5cuft cabinets for use with my existing subwoofer array.
Yes, and the beaming is designed to match the CD's directivity with the crossover
This is an OLD (2012) prototype/variation of their HTM-12 kit. They just released a new kit with a custom OEM eminence woofer that they worked on for 1.5 years... new CD... you get the idea. Check out the frequency response graph through.
Faital Pro 12PR300 + SEOS-12/DNA-360 | HiFiCircuit
I've mostly finished my Vortex-15 build. They are awesome speakers, although to anyone considering them I would probably recommend going with the spec 4cuft cabinets since the smaller ones I built result in a pretty sizable hump in the upper bass that makes them sound muddy. Not a big problem for me since I have a DSP in my signal chain for the sub crossover that can easily EQ it out. But it does somewhat limit their flexibility - I don't feel as though I have the option to use them with my AVR and its crude EQ, for example.
As to the original question of this thread, I think the Celestion compression driver used here sounds excellent. It is very smooth and not at all fatiguing, and I'm using these in nearfield about 75% of the time. It sounds great at low SPL too.
At the moment I've swapped in my SEAS Idunns while I've disassembled the Vortex-15s for finishing and while the DXT tweeter remains excellent overall, I miss the crispness of the compression driver. The Idunns do handily best the Vortex-15s in the midrange, but I kind of expected that going in and accepted the compromise.
At the moment I've swapped in my SEAS Idunns while I've disassembled the Vortex-15s for finishing and while the DXT tweeter remains excellent overall, I miss the crispness of the compression driver. The Idunns do handily best the Vortex-15s in the midrange, but I kind of expected that going in and accepted the compromise.
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